This achievement can only be obtained on Easy mode. You will come to a room with stairs on the right of the screen, at the very top a 'Giddy Goon' will spawn. You need to enter the following shortcut move correctly in order for this achievement to populate. After you press right to walk up the stairs, BEFORE the Giddy Goon appears, press up. Doing this will skip the Goon appearing and the scene will end.